In addition to this, the mechanic at Sethi motors advised to drive the AGS by letting go off the accelerator whenever it is changing gears. He told that avoid making AGS change gears, and let go off the accelerator at 20 kmh (shift to 2nd), 30 (3rd), 40 (4th) and 50 (5th), and doing this will make AGS last long, otherwise it'll need repairs in 2-3 yrs time. In pakwheels review if I remember correctly, it was mentioned that letting go off the accelerator at the right speed sends a signal to AGS to shift gear.
I have observed that by following this, I get very smooth and quiet shifts. Longevity, well it'll be known in due time.